[D2L] Final Review

Question 1

How many BTU’s in any kind of residential, commercial, or industrial gas system, including any gas appliance does a (B) gas fitter adhere to?

Answer 1

Does not exceed 400,000 BTU

Question 2

What combustible component of natural gas is typically 95%?

Answer 2

methane

Question 3

What are oil, natural gas and coal classed as?

Answer 3

hydrocarbon

Question 4

All gas contains water, which must be removed at the wellhead because it would freeze forming “hydrates”.

Answer 4

True

Question 5

How many BTU’s are required to heat a 40Gal HWT from 55F to 130F

Answer 5

30,000

Question 6

What range is the operating pressures of transmission pipe lines?

Answer 6

300 psi - 1500 psi

Question 7

Which substance is added to natural gas to provide its odor?

Answer 7

mercaptan

Question 8

What does LPG stand for?

Answer 8

liquefied petroleum gas

Question 9

What temperature does natural gas need to be at atmospheric pressure need to be in order to liquefy?

Answer 9

-258 F

Question 10

What is the boiling point of propane at atmospheric pressure?

Answer 10

-44 F

Question 11

What is the natural state of natural gas?

Answer 11

gas

Question 12

What is the heating value of natural gas?

Answer 12

1000 btu/cubic foot

Question 13

How much combustion air is needed for perfect combustion of one cubic foot of propane?

Answer 13

24 cubic feet

Question 14

Regulators of propane tanks drop the pressure between 5-10psi. What pressure does the home regulator reduce the pressure to?

Answer 14

11” wc

Question 15

Each atom of natural gas (methane) is made up of carbon and __________.

Answer 15

hydrogen

Question 16

What pressure is gas distributed in most areas of the city?

Answer 16

12 - 80 psig

Question 17

What is the Canadian Natural Gas and Propane installation code book?

Answer 17

CSA-B149.1

Question 18

When gas burns properly, the hydrogen combines with the oxygen of the air to produce water vapour. What is produced when the carbon combines with the oxygen?

Answer 18

Carbon Dioxide(CO²)

Question 19

How many cubic feet of natural gas are required to produce 400,000 btu?

Answer 19

400

Question 20

How much combustion air would be required for perfect combustion of 250,000 btu of natural gas?

Answer 20

2500 cubic feet

Question 21

What are the rough in piping pressure testing requirements for most residential piping systems (2 psi max pressure and less than 200 feet of piping)?

Answer 21

15 psi for 15 minutes

Question 22

An “A” gasfitter can work on

Answer 22

appliances and Piping downstream of the gas meter

Question 23

What is natural gases range of flammability?

Answer 23

5% to 15%

Question 24

What is the chemical formula for natural gas?

Answer 24

CH4

Question 25

Is natural gas lighter or heavier than air?

Answer 25

Lighter

Question 26

Propane gas, as a vapour, has a relative density of 1.5 lb/Ft3. Is it heavier or lighter than air?

Answer 26

Heavier

Question 27

What is the structure of a molecule of Propane?

Answer 27

Three carbon atoms and eight hydrogen atoms

Question 28

The Maximum Flame Temperature for Nat. Gas is 1000F

Answer 28

False

Question 29

What is the minimum size of pressure gauge when pressure testing rough in piping?

Answer 29

3"

Question 30

Where and how is standing pressure obtained from a gas furnace system?

Answer 30

Between the meter and the appliance with no gas flowing

Question 31

Where and how is manifold pressure obtained from a gas furnace system?

Answer 31

Between the appliance control valve and the burner while the appliance is firing

Question 32

What are the manifold pressures for natural gas and propane?

Answer 32

Natural Gas is 3.5"wc and propane is 11.0"wc

Question 33

What is the purpose of an air shutter on a mid efficient gas burner?

Answer 33

Control the amount of primary air entering the burner

Question 34

What is the purpose of aldehydes?

Answer 34

Nothing; they are a product of incomplete combustion and means carbon monoxide is likely present

Question 35

What are the three components of the combustion triangle?

Answer 35

Air, fuel and heat

Question 36

What would cause a roaring and lifting flame?

Answer 36

Too much primary air

Question 37

What are the three factors used to determine if a gas flame has the correct characteristics?

Answer 37

Colour, shape and size

Question 38

What pressure of natural gas is delivered from a service regulator to piping inside a home?

Answer 38

7"-14" wc

Question 39

How many cubic feet of propane gas is required to produce 350,000 BTU?

Answer 39

140

Question 40

What pressure is finish piping tested to?

Answer 40

working pressure

Question 41

How much is 1 psig equal to?

Answer 41

28" wc

Question 42

Vent gases are made up of:

Answer 42

Dilution Air and Flue Gases

Question 43

How much does 10 Imp Gal of water weight?

Answer 43

100 lbs

Question 44

How many hours will it take for 2000 cubic feet of propane to operate a construction heater with a rated input of 40 000 Btu per hour, if the heater operated continuously?

Answer 44

125

Question 45

What happens if we don't remove Sulphur from gas?

Answer 45

the gas produces acid rain when burned

Question 46

Propane's volume increases by how much when changing from a liquid to a vapour?

Answer 46

270x